President Donald Trump seems to be on a tariff-setting tear in recent weeks.

It all began on March 8, when the president finally followed through on an almost year-old threat to restrict imports of foreign steel.

The administration slapped a 25 percent tariff on the metal, while also putting a 10 percent duty on foreign aluminum. After initially suggesting there’d be no exceptions, Trump promised to be “very flexible” and has exempted most U.S. allies, including Mexico, Canada, the European Union and South Korea. This suggests that China is the primary target of the steel tariffs, buttressed by the other punitive measures the U.S. has taken against its biggest trading partner.

My research focuses on the politics of trade and what prompts political leaders to impose restrictions like tariffs. The last time a president slapped tariffs on steel offers an illuminating lesson – and cautionary tale – for Trump’s new policy.

President Trump holds up a proclamation on steel imports on March 8.AP Photo/Susan Walsh

The Bush steel tariffs

In early 2002, then-President George W. Bush imposed steel tariffs of up to 30 percent on imports of steel in an effort to shore up domestic producers against low-cost imports.

These tariffs were controversial both at home and abroad because, even as they helped steelmakers, they squeezed steel users, such as the auto industry.

They were also seen as hypocritical at a time when the Republican administration was trying to encourage other countries to liberalize trade policies – and reduce their tariffs – through the Doha Round of World Trade Organization talks that were happening at the time.

Transfer of wealth

So what happens when a country imposes tariffs?

The general economic view of trade protection says that tariffs transfer money from a good’s consumers to its producers.

Let’s say a country slaps a 20 percent tariff on imports of beef. The country’s beef producers will be much better off because now imported meat is as much as 20 percent more expensive, meaning domestic companies will be able to sell more rib-eyes and raise their prices. That’s bad news for restaurants and fans of steaks and hamburgers, who will pay those higher prices.

This transfer is usually economically inefficient because the benefits that domestic producers receive from a tariff will generally be less than the costs to domestic consumers.

Former President George W. Bush tours a steel factory in 2001, shortly before he imposed tariffs on foreign-made steel.Reuters/Rick Wilking

One of the reasons they still happen despite this inefficiency is that consumers are typically a very large and dispersed group. While they collectively may lose a great deal of money in higher costs from a tariff, the cost to any one individual may not be that great. Therefore, consumers are often less motivated in opposing trade protection than a relatively narrower and more unified group of producers who have a lot to gain.

The special case of steel

Steel tariffs, however, don’t follow this pattern.

That’s because far from being broadly dispersed, steel consumers are heavily concentrated in the construction and automotive industries – which have very powerful political lobbies of their own. As a result, steel consumers are more likely to balk at the higher prices that would result from tariffs.

In 2002, it was pushback from these industries that helped persuade the National Association of Manufacturers to come out against the tariffs. Eventually the World Trade Organization ruled the policy illegal because it violated U.S. trade commitments, which led to the threat of a trade war with the European Union.

The Bush administration withdrew the tariffs in December 2003, about 21 months after they were imposed, but not without a cost. The Consuming Industries Trade Action Coalition found that 200,000 workers in U.S. manufacturing lost their jobs as a result of the tariffs. For comparison, the entire U.S. steel industry employed 197,000 at the time.

During the campaign, Trump knew the value his arguments against foreign steel would have in states like Ohio.Reuters/Jonathan Ernst

The steel industry has had several things working in its favor. Trump has said repeatedly that he wants to protect American manufacturing squeezed by foreign competition, and U.S. steel certainly fits that profile. But more importantly, steel production is concentrated in old industrial states in the Midwest, such as Pennsylvania and Ohio. These states have been swing states in recent presidential elections, which gives industries with workers in those regions outsized influence.

Still, despite steel’s political advantages, tariffs are still a large gamble for Trump. While the impact of steel tariffs on other domestic manufacturers such as construction and automotive manufacturing is likely to be bad, the bigger concern is that they set off a trade war.

That would have negative consequences for American consumers and producers alike, as well as for the U.S. economy.

This article was updated on April 4 in incorporate the latest news on Trump’s tariffs.